Download MendeleyMolecular insights into the human ABCB6 transporter.
Song, G., Zhang, S., Tian, M., Zhang, L., Guo, R., Zhuo, W., Yang, M.(2021) Cell Discov 7: 55-55
- PubMed: 34312373
- DOI: https://doi.org/10.1038/s41421-021-00284-z
- Primary Citation of Related Structures:
7EKL, 7EKM - PubMed Abstract:
ABCB6 plays a crucial role in energy-dependent porphyrin transport, drug resistance, toxic metal resistance, porphyrin biosynthesis, protection against stress, and encoding a blood group system Langereis antigen. However, the mechanism underlying porphyrin transport is still unclear. Here, we determined the cryo-electron microscopy (cryo-EM) structures of nanodisc-reconstituted human ABCB6 trapped in an apo-state and an ATP-bound state at resolutions of 3.6 and 3.5 Å, respectively. Our structures reveal a unique loop in the transmembrane domain (TMD) of ABCB6, which divides the TMD into two cavities. It restrains the access of substrates in the inward-facing state and is removed by ATP-driven conformational change. No ligand cavities were observed in the nucleotide-bound state, indicating a state following substrate release but prior to ATP hydrolysis. Structural analyses and functional characterizations suggest an "ATP-switch" model and further reveal the conformational changes of the substrate-binding pockets triggered by the ATP-driven regulation.
Organizational Affiliation:
Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
